This invention involves fuel systems for internal combustion engines. A multitude of fuels have been used in internal combustion engines, including Gasoline, Propane, C.N.G. and L.N.G. (compressed and liquefied natural gas) methanol, ethanol, and hydrogen. Each of these fuels has advantages and disadvantages in their specification and use. For example, variables such as octane rating, energy content (BTU/gallon yield), flame travel velocity, storage, and refueling ease and safety, toxicity, and combustion by-product production best serve certain engine load and vehicle use scenarios, but remain a compromise in actual application.
Until now, various attempts have been made to address this problem: by using switchable fuel supplies, which are used as alternatives, such as described in U.S. Pat. Nos. 4,489,699 to Poehlman, 4,492,207 to Hallberg, or 4,535,728 to Batchelor; or by a liquid and gaseous fuel system where the selection and amount of each fuel may vary (but due to having a mechanical injection pump with only two positions, not variably or quickly enough to satisfy engine demand in real time, or change liquid fuel to gaseous form), such as described in U.S. Pat. No. 4,641,625 to Smith; or by injecting two liquid fuels, either in sequence (one to start and run a cold engine, the other to run the engine at operating temperatures), such as described in U.S. Pat. Nos. 4,546,732 to Mae and Miyauchi or 4,936,280 to Langlois; or by the phased injection into a Diesel engine of two liquid fuels of supplemental chemical properties, such as hydrogen and carbon content (e.g., alcohol and gasoline), such as described in U.S. Pat. No. 4,876,988 to Paul. There have also been attempts to aid the atomization of liquid fuel injectors, or the vaporization of carburetor or fuel injection outputs, all of which have demonstrated limitations which the present invention avoids or minimizes. The incomplete atomization of fuel injector output is primarily responsible for fuel droplets that are not reduced to a single molecule, which can then bond to a single molecule of oxidizer. Because of this incomplete combustion, unburned fuel is wasted and becomes an airborne pollutant in the form of unburned hydrocarbons (HC). Present fuel systems are inefficient because they cannot respond in real time to engine load requirements by changing the state of liquid fuels to a gaseous state, as required, or burn a second (or third) liquid or gaseous fuel, or alter the effective compression ratio of the engine cylinders, or precisely meter additional air into the engine, as fuel supplies, engine demands, and operating conditions dictate. To compensate for their compromised combustion characteristics, present fuel systems employ such add-on devices as catalytic converters and E.G.R. (exhaust gas recirculation), to control such pollutants as carbon monoxide (CO), oxides of nitrogen (NOx), and unburned hydrocarbons (HC). The present invention also offers increased safety, because the fuel cylinder which contains natural gas or methane can be made smaller, stronger, and lighter. Since this fuel cylinder is smaller, it may also be re-charged more quickly, and, in fact, is designed to be charged overnight (in 3 to 5 hours), by a small gas compressor which is connected to residential or business gas mains. This feature enables the vehicle to be available the next morning for "typical" commuting distances of 30-50 miles (round trip). Because of this, it is entirely conceivable that drivers would never use gasoline supplies, except for long distances (even the 30-50 mile limitation could be avoided by the installation of parking facility refueling stations). Because methane can be easily substituted for natural gas, garbage, sewage, biomass wastes, and other non-strategic resources can be used to produce methane, reducing landfill and sewage treatment environmental pollutants. Finally, the present invention easily adapts to the present generation of automobiles, with their heavy investments in technology and tooling, as well as their demonstrated consumer appeal.